Driver contact vibrator



Sept. 27, 1949. k c. F. COAKE 2,483,086

DRIVER OONTAGT VIBRATOR Filed Dec. 20, 1944 2 Sheets-Sheet 50 i0 28? 6d: ANNE mfhzj 26 25 24 Nee I 86' INVENTOR.

CH/IRLEJ ECO/4 KE "wwwm ATTORNEY Sept. 27, 1949. c. co 2,483,086

DRIVER CONTACT VIBRATOR Filed Dec. 20, 1944 2 Sheets-Sheet 2 ATTORNEY Patented Sept. 27, 1949 muvna CONTACT VIBRATOR Charles F. Coake, Indianapolis, Ind., assignor to Sen Corporation, New Augusta, Ind., a corporation of Indiana Application December 20, 1944, Serial No. 569,033

6 Claims. (01. 72 ,426)

source into high voltage which after subsequent rectification and filtering may provide plate and biasing voltages for vacuum tubes of a radio transmitter to receiver. Th trend of the development of the art was in the direction of pro viding vibratory interrupters of increasing power handling ability and eillciency in order to con- .-vert relatively heavy low voltage currents into high voltage currents with negligible power losses. In vibrators of this type it was found desirable to keep the driver circuit distinct and independent from the power circuit and to assign a separate driver contact for controlling the circuit of the driver electromagnet and thereby to obtain continuous vibratory motion of the reed.

In prior driver contact vibrators the dr ver contact was generally carried by an auxiliary reed secured to the principal reed. This driver contact was so associated with the circuit of the driver electromagnet that in the normal position of rest the circuit of the electromagnet was closed, thereby energizing the electromagnet and defleeting the reed. This in turn interrupted the driver circuit and would cause the reed to return to its original position and in fact to swing beyond the same, thereby restoring continuity of the driver circuit. Broadly stated, the driver circuit was closed for about onehalf cycle and was open for about one-half cycle during a full operative period. Obviously, the current flowing in the driver circuit was drawn from the low voltage source in addition to the current flow in the primary winding of the step-up transformer and represented a power loss cutting down the overall elliciency of the system. For this reason, it was conventional practice to employ a driver electromagnet of relatively high resistance and thereby to keep the driver circuit current at a minimum. This howevenw-as only possible to a very limited extent because the low amount of energy which might have been suilicient to maintain the reed in continuous vibration during the steady-state operation was lrequently insuilicient to positively assure quick starting of the vibrator and was a frequent source of operating difliculties. Moreover, at least a portion of the period during which the driver electromagnet was energized coincided with the time during which the reed swinging back from one extreme position has already passed beyond the midpoint of its travel and was moving away from the pole of the driver electromagnet. In this period the energized condition of the driver circuit has actually hindered the swing of the reed into its other extreme position and has represented a total loss of energy. Although these diiiiculties were well known to those skilled in the art and from time to time various suggestions and proposals were made to eliminate the same, none of these suggestions and proposals was completely satisfactory and successful on a practical and commercial scale.

It is an object of the present invention to provide a novel vibrator organization which completely eliminates the foregoing difiiculties and inconveniences connected with the design and the operation of prior driver contact vibrators.

It is another object of the present invention to provide a driver contact vibrator of novel and improved character in which the period during which thedriver circuit is closed and consumes energy is substantially reduced.

It is a further object of the invention to provide a driver contact vibrator in which a principal reed is combined with a pair of auxiliary reeds into a unitary vibratory structure, one of said auxiliary reeds bearing a driver contact, while the other auxiliary reed acts as a stop finger causing interruption of the driver circuit at a determined time with respect to the vibratory displacement of the principal reed, thereby reducing the period duringwhich the driver circuit is maintained closed.

It is also within contemplation of the invention to provide a driver contact vibrator in which the natural or fundamental frequency of the principal and of the auxiliary reeds and the mass of the armature and oi the driver contact are so adjusted with respect to each other and to the driver circuit constants that a very high starting ability is combined with a low steady-state current, thereby realizing a heretofore unobtainable efllciency of current conversion.

The invention also contemplates a driver contact vibrator of high eiflciency which is simple in structure, positive in operation, and which may be readily manufactured and sold on a practical and commercial scale at a low cost.

Other and further objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing; in which Fig. 1 illustrates an expanded perspective view of a vibratory reed embodying the principles of the present invention;

Fig. 2 depicts a side elevational view of the reed structure shown in Fig. l in its assembled condition:

Fig. 3 shows a circuit diagram of the novel vibratory interrupter organization; and

Figs. 4 to 8 illustrate the relative positions of the principal reed and auxiliary reeds during successive stages of the operation cycle.

Referring now more particularly to Figs. 1 and 2 of the drawing, reference character Ill denotes a principal reed having an armature H mounted at the upper or free end thereof and having a pair of downwardly depending ears l2 at the lower or clamped end thereof. These depending portions are connected to the body of the reed by means of weakened portions l3 and have clamping holes l4 provided therein. An elongated slot l5 extends throughout the major portion of the length of the reed. Auxiliary reed I6 is of an inverted T-shape and has two mounting holes I! in the transverse portion thereof conforming to correspondingly spaced holes [8 in the body of the principal reed. The upper end of auxiliary reed I6 bears a driver contact IS. The second auxiliary reed 20 is similar in shape to auxiliary reed l6 and has a pair of similar mounting holes 2| in its transverse portion. Auxiliary reed 20, however, ends short of auxiliary reed l6 and constitutes a stop finger adapted to cooperate with corresponding portions of auxiliary reed is below driver contact l9, as it will be explained more fully hereinafter. The reed structure is completed by a pair of U-shaped side arms 23 hearing two power contacts 24 each and having mounting holes 25. The principal reed, the auxiliary reeds and the side arms are held to ether by means of bolts or rivets 26 in the position illustrated in Fig. 2.

The cooperation of the novel reed structure with an electro-magnetic vibratory interrupter will be best understood by referring to Fig. 3 showing a preferred form of circuit organization. A source of low voltage 30 has one of its terminals connected to reed i0 and its other terminal connected to the midpoint of the primary winding 3| of a step-up transformer 32. The high voltage alternating current is taken off at the terminal points of secondary winding 33 of the transformer, grounded at its mid oint and having a buffer condenser 34 connected across the same in conventional manner. This alternating current may be rectified by means of a vacuum tube rectifier or by means of synchronous contacts (not shown) provided on the vibratory reed. Vibratory power contacts 24 carried by side arms 23 coo erate with relatively fixed contacts 35, respectively connected to the ends of primary winding 3| of the transformer. v

The driver circuit of the vibrator comprises a relati ely fixed cont ct 36 coo erating with driver contact IS on auxiliary reed l6 and connected with winding 31 of the driver electromagnet having an iron-core 38 one end of which is arranged in close proximity to armature ll of principal reed Hi. The other end of winding 31 is connected to one terminal of the low voltage source 30.

From the foregoing description, the operation of the novel vibratory reed and its circuit organization will be readily understood by those skilled in the art. In the normal position of rest the driver circuit is closed between driver contact I! and fixed contact 36 and current will flow from the negative terminal of the current source through auxiliary reed l6, driver contact 13, fixed contact 38, electromagnet winding 31 and back to the positive terminal of the source. Winding 31 being energized, the end of iron core 33 will attract armature H and will deflect the principal reed and the auxiliary reeds mounted thereon. It will be noted that the combination of the two auxiliary reeds I6 and 20 will provide a reed structure and support for driver contact I! which is relatively rigidly connected to the principal reed Ill during the upward travel thereof and is relatively yielding with respect to said principal reed during the downward travel thereof. Therefore, during the upward displacement of the principal reed the driver contact will closely follow the principal reed and will break the driver circuit between I9 and 36 at approximately the time when the principal reed reaches the midpoint of its displacement and possibly before such position. Due to its inertia the principal reed and also the driver contact will swing beyond the midpoint and will reach its greatest upward deflection. During its return travel, however, driver contact l9 will lag behind the principal reed and will not catch up with it until the principal reed has practically reached the lower point where its direction is reversed. This lagging of the driver contact is the result of the cooperation of various factors. First, the mass of the driver contact I 3 loads the free end of auxiliary reed l3 and introduces a suflicient amount of inertia which prevents this auxiliary reed from instantaneously following any change in the direction or speed of the displacement of the principal reed. In addition to this, during this downward travel, auxiliary reed I3 is substantially disconnected from the other auxiliary reed, or stop finger 20, so that its flexibility and its freedom of displacement with respect to the principal reed are greatly increased. The result will be that the driver circuit will be closed only during the relatively short period while armature ii is under the influence of the energized electromagnet 31 and is traveling from its lowest point up to its midpoint. Generally speaking, this period of closed driver circuit does not exceed one-quarter cycle and may be even less, in contrast to the conventional mode of operation where the driver circuit is closed for a period greatly exceeding one-quarter cycle and is of the order of one-half cycle.

It has been found that this highly desirable and novel operating condition is further supplemented and assured by providing predetermined and definite frequency relations between the frequency of the driver contact and that of the principal reed. Thus, it is preferred to so adjust this frequency relation that the fundamental frequency of the driver contact is less than that oi. the principal reed, preferably equaling one-hali to one times the principal reed frequency. As a modification of this concept, the frequency of the driver contact may be made higher than the fundamental frequency of the principal reed by an odd ratio, such as for example two and one-half to one. In this case the driver circuit will not be closed until the principal reed has reached the lower terminal point of its swing.

It will be noted that the principles of the invention provide various important advantages. Thus, first of all, due to the greatly reduced period during which the driver contacts and the driver circuit are closed, the amount of heat generated in the driver coil is greatly reduced. Since the driver coil does not hinder the downward travel aeaaoae of the reed structure, much less energy is required for maintaining the reeds in vibratory motion whereby the overall emciency of conversion is substantially increased.

It is also to be observed that the lower amount of heat generated in the driver coil permits provision for higher ampere turns of the driver electromagnet, this considerably aiding in starting. At the same time such higher starting power is obtained without the necessity of employing higher steady-state amplitudes of the driver current, which is an idealcondition of operation heretofore unobtainable with conventional reed structures.

Moreover, the novel reed structure is extremely simple in construction and in fact is much safer and more positive in operation than any one of the prior reed organizations.

Figures 4 to 8 illustrate the relative positions of the principal reed i and auxiliary reeds I, during successive stages of the operating cycle. In the structure shown by these figures, the fun- A damental frequency of the auxiliary reed I8 is substantially less than that of the principal reed III. In the initial position shown by Figure 4, the reeds it and 20 are in engagement and the contacts I9, I are closed. As the principal reed travels upwardly in the direction indicated by the arrow, Figure 4, in response to energization of the driver coil, the three reeds move as a unit until an upper extreme position is reached which is shown in Figure 5, the reed 20 lifting the auxiliary reed it along with the contact l9. Thereupon, the principal reed II and reed 20 move downwardly, the successive positions thereof being indicated in Figures 6 to 8. The auxiliary reed l6 lags behind the principal reed during this downward motion since, as stated, the fundamental frequency of the auxiliary reed is substantially less than that of the principal reed. At or shortly after the time the principal reed reaches its lowermost position, Figure 8, the auxiliary reed reaches a position where the contact it engages the contact 86 and these contacts remain in engagement while the principal reed moves upwardly to the initial position shown by Figure 4. Thereupon, the reed member II again engages the auxiliary reed I. and the three reeds move up wardly as a unit to initiate another cycle of operation.

It will be apparent that the contacts It, it are closed for approximately one-fourth of the operating cycle and that the length of the closed contact period may be varied by adjusting the fundamental frequencies of the principal reed ill and auxiliary read it.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

1. A vibratory interrupter comprising in combination a principal reed having an elongated longitudinal slot therein, a pair of auxiliary reeds of inverted T-shape having their transverse portions respectively mounted on said principal reed and having their longitudinal portions extending into and displaceable through said slot, one of said auxiliary reeds bearing a driver contact and the other ending short of said contact, and electromagnetic means under the control of said driver contact for maintaining said principal reed in vibratory motion, the shorter one of said auxilment with each other during a portion of each iary reeds constituting a stop finger substantially preventing vibration of the other auxiliary reed when the principal reed moves in driver circuitopening direction but being substantially inefl'ective to prevent vibration of the longer auxiliary reed when the principal reed is moving in the opposite direction whereby the driver contact will lag behind the principal reed during the'return swing thereof and will reduce the period during which the driver circuit is closed below one-half cycle.

2. A vibratory interrupter comprising in combination a principal reed having an elongated longitudinal slot therein, a pair of auxiliary reeds having a transverse portion respectively secured to the two sides of said principal reed and having longitudinal portions of unequal length extending into and flexible within said slot in substantially aligned position, the longer one of said auxiliaryreeds bearing a driver contact and the shorter one forming a stop finger therefor, and a relatively fixed contact for said driver contact, electromagnetic means under the control of said driver contact to maintain said principal reed in vibratory motion, the mass of said driver contact and the resiliency of the auxiliary reeds being so determined that the driver contact will lag behind the principal reed during its swing toward driver contact-closing position whereby the period dur ing which the driver circuit is closed is reduced to the order of one-quarter cycle.

3. A vibratory interrupter comprising in combination a principal reed having an aperture therein, a pair of auxiliary reeds having one of their ends mounted on said principal reed and having their other end relatively displaceable thereto, said auxiliary reeds being adapted for engagement with each other through said aperture during a portion of each operating cycle. a driver contact on one of said auxiliary reeds, a fixed contact adapted to cooperate with said driver contact, and electromagnetic means controlled by said driver contact to maintain said reeds in vibratory motion, the fundamental frequency of said driver contact reed being adjusted to a value lower than that of said principal reed.

4. A vibratory interrupter comprising in combination an apertured principal reed clamped at one end thereof, an auxiliary reed structure including a pair of auxiliary reeds of diiferent lengths, each having one end fixed to said principal reed near the clamped end thereof and having the other end relatively displaceable thereto,

said auxiliary reeds being adapted for engageoperating cycle, a driver contact on one of said auxiliary reeds, a relatively fixed contact adapted to cooperate with said driver contact, and electromagnetic means under the control of said driver contact to maintain said reeds in vibratory motion, the fundamental frequency of said driver contact reed being higher by an odd ratio than that of said principal reed whereby said electromagnetic means will be energized for a period of the order of one-quarter cycle for each cycle of the principal reed.

5. In a driver contact vibrator havin a vibratory principal reed adapted to control a power circuit and an electromagnetic driver circuit therefor, the improvement which comprises a composite auxiliary reed bearing a driver contact, the components of said auxiliary reed having asymmetrical flexibility characteristics for flexure in two opposite directions, the relative fundamental frequencies of principal and auxiliary reed 7 beingso adjusted that in-phase operation of acid reeds will result in driver contact-breaking direction and out-ot-phase operation of said reeds will result in driver contact-making direction whereby the driver circuit will be energized for about onequarter cycle for each cycle of the principal reed.

8. In a driver contact vibrator having a vibratory principal reed adapted to control a power circuit and an electromagnetic driver circuit therefor, the improvement which comprises a composite auxiliary reed constituted of a pair of aligned reeds of unequal length mounted on said principal reed, and a driver contact on the longer one of said auxiliary reeds, the relative fundamental frequencies of said principal and auxiliary reeds being so adjusted that in-phase operation of said reeds will result in the driver circuit-break ing direction and out-oi-phase operation of said reeds will result in the driver circuit-closing 

